121563261 has 10 divisors (see below), whose sum is σ = 181594622. Its totient is φ = 81042120.

The previous prime is 121563229. The next prime is 121563263. The reversal of 121563261 is 162365121.

121563261 is a `hidden beast` number, since 1 + 21 + 5 + 632 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 114704100 + 6859161 = 10710^2 + 2619^2 .

It is not a de Polignac number, because 121563261 - 2⁵ = 121563229 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121563263) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 750310 + ... + 750471.

Almost surely, 2^121563261 is an apocalyptic number.

It is an amenable number.

121563261 is a deficient number, since it is larger than the sum of its proper divisors (60031361).

121563261 is an equidigital number, since it uses as much as digits as its factorization.

121563261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1500793 (or 1500784 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 121563261 is about 11025.5730463319. The cubic root of 121563261 is about 495.3750325924.

The spelling of 121563261 in words is "one hundred twenty-one million, five hundred sixty-three thousand, two hundred sixty-one".